Initial import of Dillo

lout/object.cc

@@ -0,0 +1,386 @@
+/*
+ * Dillo Widget
+ *
+ * Copyright 2005-2007 Sebastian Geerken <sgeerken@dillo.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+
+#include "object.hh"
+#include "dlib/dlib.h"
+#include <stdio.h>
+#include <stdint.h>
+#include <config.h>
+
+namespace lout {
+
+namespace object {
+
+// ------------
+//    Object
+// ------------
+
+/**
+ * \brief The destructor is defined as virtual (but not abstract), so that
+ *    destruction of Object's works properly.
+ */
+Object::~Object()
+{
+}
+
+/**
+ * \brief Returns, whether two objects are equal.
+ *
+ * The caller should ensure, that this and the object have the same class;
+ * this makes casting of "other" safe. Typically, an implementation should
+ * check this == other first, the caller can assume a fast implementation.
+ */
+bool Object::equals(Object *other)
+{
+   misc::assertNotReached ();
+   return false;
+}
+
+/**
+ * \brief Return a hash value for the object.
+ */
+int Object::hashValue()
+{
+   fprintf (stderr, "Object::hashValue() should be implemented.\n");
+   return 0;
+}
+
+/**
+ * \brief Return an exact copy of the object.
+ */
+Object *Object::clone()
+{
+   misc::assertNotReached ();
+   return NULL;
+}
+
+/**
+ * \brief Use object::Object::intoStringBuffer to return a textual
+ *    representation of the object.
+ *
+ * The caller does not have to free the memory, object::Object is responsible
+ * for this.
+ */
+const char *Object::toString()
+{
+   /** \todo garbage! */
+   misc::StringBuffer sb;
+   intoStringBuffer(&sb);
+   char *s = dStrdup(sb.getChars());
+   return s;
+}
+
+/**
+ * \brief Store a textual representation of the object in a misc::StringBuffer.
+ *
+ * This is used by object::Object::toString.
+ */
+void Object::intoStringBuffer(misc::StringBuffer *sb)
+{
+   sb->append("<not further specified object ");
+   sb->appendPointer(this);
+   sb->append(">");
+}
+
+/**
+ * \brief Return the number of bytes, this object totally uses.
+ */
+size_t Object::sizeOf()
+{
+   fprintf (stderr, "Object::sizeOf() should be implemented.\n");
+   return sizeof(Object*);
+}
+
+// ----------------
+//    Comparator
+// ----------------
+
+Comparator *Comparator::compareFunComparator = NULL;
+
+/**
+ * \brief This static method may be used as compare function for
+ *    qsort(3) and bsearch(3), for an array of Object* (Object*[] or
+ *    Object**).
+ *
+ * "compareFunComparator" should be set before.
+ *
+ * \todo Not reentrant. Consider switching to reentrant variants
+ * (qsort_r), and compare function with an additional argument.
+ */
+int Comparator::compareFun(const void *p1, const void *p2)
+{
+   return compareFunComparator->compare (*(Object**)p1, *(Object**)p2);
+}
+
+// ------------------------
+//    StandardComparator
+// ------------------------
+
+int StandardComparator::compare(Object *o1, Object *o2)
+{
+   if (o1 && o2)
+      return ((Comparable*)o1)->compareTo ((Comparable*)o2);
+   else if (o1)
+      return 1;
+   else if (o2)
+      return -1;
+   else
+      return 0;
+}
+
+StandardComparator standardComparator;
+
+// -------------
+//    Pointer
+// -------------
+
+bool Pointer::equals(Object *other)
+{
+   return value == ((Pointer*)other)->value;
+}
+
+int Pointer::hashValue()
+{
+/* For some unknown reason, this doesn't compile on some 64bit platforms:
+ *
+ *  if (sizeof (int) == sizeof (void*))
+ *     return (int)value;
+ *  else
+ *     return ((int*)&value)[0] ^ ((int*)&value)[1];
+ */
+#if SIZEOF_VOID_P == 4
+   // Assuming that sizeof(void*) == sizeof(int); on 32 bit systems.
+   return (int)value;
+#else
+   // Assuming that sizeof(void*) == 2 * sizeof(int); on 64 bit
+   // systems (int is still 32 bit).
+   // Combine both parts of the pointer value *itself*, not what it
+   // points to, by first referencing it (operator "&"), then
+   // dereferencing it again (operator "[]").
+   return ((intptr_t)value >> 32) ^ ((intptr_t)value);
+#endif
+}
+
+void Pointer::intoStringBuffer(misc::StringBuffer *sb)
+{
+   char buf[64];
+   snprintf(buf, sizeof(buf), "%p", value);
+   sb->append(buf);
+}
+
+// -------------
+//    Integer
+// -------------
+
+bool Integer::equals(Object *other)
+{
+   return value == ((Integer*)other)->value;
+}
+
+int Integer::hashValue()
+{
+   return (int)value;
+}
+
+void Integer::intoStringBuffer(misc::StringBuffer *sb)
+{
+   char buf[64];
+   sprintf(buf, "%d", value);
+   sb->append(buf);
+}
+
+int Integer::compareTo(Comparable *other)
+{
+   return value - ((Integer*)other)->value;
+}
+
+// -------------
+//    Boolean
+// -------------
+
+bool Boolean::equals(Object *other)
+{
+   bool value2 = ((Boolean*)other)->value;
+   // TODO Does "==" work?
+   return (value && value2) || (!value && value2);
+}
+
+int Boolean::hashValue()
+{
+   return value ? 1 : 0;
+}
+
+void Boolean::intoStringBuffer(misc::StringBuffer *sb)
+{
+   sb->append(value ? "true" : "false");
+}
+
+int Boolean::compareTo(Comparable *other)
+{
+   return (value ? 1 : 0) - (((Boolean*)other)->value ? 1 : 0);
+}
+
+// -----------------
+//    ConstString
+// -----------------
+
+bool ConstString::equals(Object *other)
+{
+   ConstString *otherString = (ConstString*)other;
+   return
+      this == other ||
+      (str == NULL && otherString->str == NULL) ||
+      (str != NULL && otherString->str != NULL &&
+       strcmp(str, otherString->str) == 0);
+}
+
+int ConstString::hashValue()
+{
+  return hashValue(str);
+}
+
+
+int ConstString::compareTo(Comparable *other)
+{
+   String *otherString = (String*)other;
+   if (str && otherString->str)
+      return strcmp(str, otherString->str);
+   else if (str)
+      return 1;
+   else if (otherString->str)
+      return -1;
+   else
+      return 0;
+}
+
+
+int ConstString::hashValue(const char *str)
+{
+   if (str) {
+      int h = 0;
+      for (int i = 0; str[i]; i++)
+         h = (h * 256 + str[i]);
+      return h;
+   } else
+      return 0;
+}
+
+void ConstString::intoStringBuffer(misc::StringBuffer *sb)
+{
+   sb->append(str);
+}
+
+// ------------
+//    String
+// ------------
+
+String::String (const char *str): ConstString (str ? dStrdup(str) : NULL)
+{
+}
+
+String::~String ()
+{
+  if (str)
+    free((char *)str);
+}
+
+// ------------
+//    Pair
+// ------------
+
+PairBase::PairBase(Object *first, Object *second)
+{
+   this->first = first;
+   this->second = second;
+}
+
+PairBase::~PairBase()
+{
+   if (first)
+      delete first;
+   if (second)
+      delete second;
+}
+
+bool PairBase::equals(Object *other)
+{
+   PairBase *otherPair = (PairBase*)other;
+
+   return
+      // Identical?
+      this == other || (
+      (// Both first parts are NULL, ...
+         (first == NULL && otherPair->first == NULL) ||
+         // ... or both first parts are not NULL and equal
+         (first != NULL && otherPair->first != NULL
+          && first->equals (otherPair->first))) &&
+      // Same with second part.
+      ((second == NULL && otherPair->second == NULL) ||
+       (second != NULL && otherPair->second != NULL
+        && second->equals (otherPair->second))));
+}
+
+int PairBase::hashValue()
+{
+   int value = 0;
+
+   if (first)
+      value ^= first->hashValue();
+   if (second)
+      value ^= second->hashValue();
+
+   return value;
+}
+
+void PairBase::intoStringBuffer(misc::StringBuffer *sb)
+{
+   sb->append("<pair: ");
+
+   if (first)
+      first->intoStringBuffer(sb);
+   else
+      sb->append("(nil)");
+
+   sb->append(",");
+
+   if (second)
+      second->intoStringBuffer(sb);
+   else
+      sb->append("(nil)");
+
+   sb->append(">");
+}
+
+size_t PairBase::sizeOf()
+{
+   size_t size = 0;
+
+   if (first)
+      size += first->sizeOf();
+   if (second)
+      size += second->sizeOf();
+
+   return size;
+}
+
+} // namespace object
+
+} // namespace lout